The present invention relates to pneumatic continuity testers and more specifically to a pneumatic continuity tester on an electrically controlled pneumatic train brake system.
The brake pipe continuity between the head end unit and the end of train unit must be checked before a train can leave the yard. This method has included connecting the train brake to a source of external air, charging the brake pipe and determining at the end of train whether it received and maintains the charge. With the addition of the end of train device which includes a radio and pressure sensor that can report the pressure at the end of train, an engineer standing at the beginning of the train can pressurize the train brake pipe using the charging system at the head end and monitor the pressure at the end of train device. In both of these types of tests, if the end of train device does not monitor the appropriate pressure, there is a disruption in the brake pipe and the crew would have to walk the train to determine where the continuity of the brake pipe has been interrupted.
For long trains, there may be more than one locomotive distributed throughout the train. Each locomotive is equipped with charging equipment and a controller. Thus, each locomotive can control the brake pipe and monitor the continuity locally. These type of systems require that the locomotive have a continuity testing capability in addition to a charge capability. This would make the ability to perform the continuity test dependent on the equipment on the individual locomotives. With the advent of electrically controlled pneumatic brakes, ECP, each brake system on the car would include a pressure sensor and a communication device on the network capable of commuting to a head end unit or locomotive. Thus, multiple pressure sensors are available throughout the train between the head end unit and the end of train device.
The present invention takes advantage of the electrically controlled pneumatic brake system on the train to provide a method of determining brake pipe continuity independent of the capability of other units within the train to determine continuity. The system determines continuity from a head end unit to an end of train unit using a plurality of intermediate brake pipe monitoring and charging devices, all connected in a network with the head end unit end of train unit. The method includes reducing pressure of a charged brake pipe to a predetermined pressure value. The brake pipe is then charged only from the head end unit. Each intermediate brake pipe monitoring and charging device sequentially reports on the network a pressure which is an increase if the brake pipe is continuous between it and the head end unit. Subsequent to receipt of a report of an increased pressure on the network from an intermediate unit, the head end unit commands that intermediate unit to participate in charging the brake pipe. The head end unit determines the brake pipe continuity from the pressure increases reported by the intermediate units. The brake pipe pressure at the end of train device is monitored and reported to the head end unit. The initial charging of the brake pipe uses the head end unit and some, if not all of the intermediate units.
There is a dwell period of time between the brake pipe reduction and the charging with the head end unit only. A plurality of brake pipe monitors are also provided between the head end unit and the end of train device on the network and each reports brake pipe pressure on the network. The head end unit can also develop a brake pipe signature from the reported pressure increases.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.